Comparison of compressive strength between two mini implants :an in vitro study

Abstract

Objective: To observe and evaluate the difference in static and dynamic loadings between two mini-implant systems (RetenDent and MS denture® system, OSSTEM). Materials and Methods: Fifty mini-implant from two companies were included in the study. The compressive force was applied to the mini-implants at 30 degrees from its vertical axis. Ten specimens from each group were subjected to static load tests. Subsequently, five cyclic loadings were calculated from static compressive strength. These loads include 320N, 275N, 230N, 185N, and 140N. Three specimens from each group were randomly selected and tested at each loading condition. The Independent T- test was utilized to obtain the statistical differences of the static compressive strength, while descriptive statistics was utilized to compare the difference of dynamic loading between two mini-implant systems. Results: The average static compressive strengths of RetenDent and OSSTEM mini-implants were 462.969 + 16.73 N and 403.407 + 25.55 N, respectively. Overall, RetenDent demonstrated a higher number of survived cycles except at 320N loading condition compared to OSSTEM. The fatigue limit of RetenDent and OSSTEM mini-implants was defined at 185N and 140N, respectively. Conclusion: RetenDent has higher static and dynamic compressive strength compare to OSSTEM. Both RetenDent and OSSTEM’s static and dynamic compressive strength were greater than maximum bite force of implant-retained overdenture. RetenDent mini-implants is likely to has capabilities in need for application in clinical practice to retain prostheses.